| Date | Mon, 25 Mar 2013 01:05:51 +0000 | From | Ben Hutchings <> | Subject | [ 027/104] tools: hv: Netlink source address validation allows DoS |
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3.2-stable review patch. If anyone has any objections, please let me know.
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From: Tomas Hozza <thozza@redhat.com>
commit 95a69adab9acfc3981c504737a2b6578e4d846ef upstream.
The source code without this patch caused hypervkvpd to exit when it processed a spoofed Netlink packet which has been sent from an untrusted local user. Now Netlink messages with a non-zero nl_pid source address are ignored and a warning is printed into the syslog.
Signed-off-by: Tomas Hozza <thozza@redhat.com> Acked-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- tools/hv/hv_kvp_daemon.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
--- a/tools/hv/hv_kvp_daemon.c +++ b/tools/hv/hv_kvp_daemon.c @@ -393,13 +393,19 @@ int main(void) len = recvfrom(fd, kvp_recv_buffer, sizeof(kvp_recv_buffer), 0, addr_p, &addr_l); - if (len < 0 || addr.nl_pid) { + if (len < 0) { syslog(LOG_ERR, "recvfrom failed; pid:%u error:%d %s", addr.nl_pid, errno, strerror(errno)); close(fd); return -1; } + if (addr.nl_pid) { + syslog(LOG_WARNING, "Received packet from untrusted pid:%u", + addr.nl_pid); + continue; + } + incoming_msg = (struct nlmsghdr *)kvp_recv_buffer; incoming_cn_msg = (struct cn_msg *)NLMSG_DATA(incoming_msg);
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